What is the difference between memetic algorithms and genetic algorithms?
A genetic algorithm is an algorithm, based on natural selection (the process that drives biological evolution), for solving both constrained and unconstrained optimization problems.
A memetic algorithm is an extension of the concept of a genetic algorithm that uses a local search technique to reduce the likelihood of premature convergence.
The paper A Comparison between Memetic algorithm and Genetic algorithm for the cryptanalysis of Simplified Data Encryption Standard algorithm compares both approaches.
To answer your last question, yes, an individual's lifetime still plays a part in memetic algorithms because the objective here is to avoid premature convergence.